Technique for high efficiency metalorganic chemical vapor deposition

ABSTRACT

A technique for more efficiently forming conductive elements, such as conductive layers and electrodes, using chemical vapor deposition. A conductive precursor gas, such as a platinum precursor gas, having organic compounds to improve step coverage is introduced into a chemical vapor deposition chamber. A reactant is also introduced into the chamber that reacts with residue organic compounds on the conductive element so as to remove the organic compounds from the nucleating sites to thereby permit more efficient subsequent chemical vapor deposition of conductive elements.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to semiconductor processing and, inparticular, concerns a metalorganic chemical vapor deposition (MOCVD)technique for forming component layers, such as platinum layers, in amanner that results in more efficient deposition of the component layeronto the surface of a semiconductor device.

[0003] 2. Description of the Related Art

[0004] Semiconductor processing techniques have become increasingly morecomplex as a result of the increasing density and smaller sizes ofsemiconductor devices. One particular problem that occurs with smallersized semiconductor devices is that it is often difficult to formcomponents, such as conductors, vias and electrodes, that conformallycover the contours of the semiconductor device. For example, a typicaldevice formed by semiconductor processing is a capacitor. Typically, acapacitor is formed in an opening in an isolation layer of asemiconductor device and has two electrodes that are positioned withinthe opening with a dielectric separating the electrodes so as to coverboth the side walls and the bottom floor of the opening. It will beappreciated that as the openings become smaller and smaller in size, itis increasingly more difficult to have the electrode formed so as touniformly cover the side walls and bottom walls of the opening. Threedimensional capacitors are but one example of a device that isincreasingly more difficult to fabricate due to decreasing devicedimensions leading to difficulties with conformal covering of the devicesurface. Other devices in which this problem occurs include vias,electrodes and conductive lines.

[0005] To address the particular problems associated with formingelectrodes and other conductive elements on 3-dimensional surfaces,various techniques using various materials have been developed. Oneparticularly common technique for forming three dimensional conductiveelements, vias and lines in semiconductor applications is to useChemical Vapor Deposition (CVD) techniques to deposit a conductivematerial, such as platinum (Pt), within an opening formed to contain a3-dimensional conductive element.

[0006] For example, platinum is viewed as an ideal electrode materialfor high-K capacitors in DRAM applications due to its relatively highwork function. This high work function forms an increased energy barrierinhibiting leakage migration of charge carriers between electrodesthrough an intervening dielectric. Moreover, platinum is also generallynot oxidizable such that the electrode's resistivity is not increased asa result of exposure to oxygen containing compounds contained within thesemiconductor environment.

[0007] Further, platinum is also strongly favored for formation ofelectrodes and 3-dimensional semiconductor structures, such ascapacitors, conductors, vias and the like, due to its particularlyadvantageous step coverage when applied using chemical vapor deposition(CVD) techniques. In particular, platinum can be used to coat3-dimensional structures through chemical vapor deposition such that thevertical side walls and the horizontal bottom surfaces are adequatelycovered by the deposited platinum.

[0008] Typically, a platinum precursor and other reactants areintroduced into the CVD chamber and the platinum carried by a precursorgas is then deposited onto the surface of the semiconductor substratethrough thermal decomposition or reaction with another reactant gas,such as O₂, N₂O, or H₂. The platinum is carried in the precursor gas,that often comprises an organic compound. The platinum atom is bonded tothe organic compound to permit the platinum atoms to be transferred inthe gas phase. This enables the Pt to be conformally deposited over thesurface of the wafer as the organic compound facilitates improved stepcoverage.

[0009] In the prior art, there is generally only a single depositionstep such that the precursor gas and other reactant gas(es) are flowedinto the CVD chamber until enough platinum, carried by the precursorgas, has been deposited on the exposed surface to form an electrode orother conductive element of a desired thickness. However, current CVDplatinum deposition techniques have particularly low depositionefficiency such that the deposition rate is very slow, on the order of 1Angstrom per second. In order to obtain a 300 Angstrom film, thedeposition time is therefore usually several minutes. The relativelyslow deposition rate creates inefficiencies in the manufacturing ofsemiconductor devices.

[0010] Moreover, the platinum precursor gas used for deposition isparticularly expensive, on the order of $100 per gram. It has beenobserved that typical CVD platinum deposition techniques result inenormous waste of this expensive platinum precursor gas as only a smallproportion of the platinum carried by the precursor gas is actuallybeing deposited on the semiconductor wafer positioned in the CVDchamber. Hence, not only are current CVD platinum deposition techniquesslow, they are also particularly inefficient in delivering platinum tothe wafer. This results in considerable waste of expensive material andincreases the cost of manufacturing semiconductor devices that require3-dimensional conductive structures, like electrodes or conductors.

[0011] Further, the deposition process also results in the possibledeposition of hydrocarbon byproducts on the surface of the semiconductordevice which can become incorporated into or adsorbed onto the surfaceof the deposited film contaminating the film and inhibiting furtherdeposition. In particular, the deposition of platinum in one typicalprocess proceeds by the formula:

(C₅H₅)Pt(CH₃)₃+H₂→Pt(film)+CH₄+other hydrocarbons

[0012] The other hydrocarbons may not be volatile enough at thedeposition temperature and thus stay on the surface of the filmfollowing deposition. This can result in contamination of the film andinhibit further deposition of the platinum film.

[0013] From the foregoing, it will be appreciated that there is a needfor an improved technique for depositing conductive materials onto asemiconductor surface such that good step coverage can be obtainedwithout a significant increase in the cost of manufacturing thesemiconductor device. To this end, there is a need for a more efficientway of depositing conductive material, such as platinum, in a mannerthat results in more efficient deposition of the material with lesswaste of the precursor material used to form the material.

SUMMARY OF THE INVENTION

[0014] The aforementioned needs are satisfied by the present inventionwhich, in one aspect, comprises a method of forming a conductive layercomprising (a) positioning a semiconductor device within a CVD chamber,(b) exposing the semiconductor device to a precursor gas containing aconductive element and a reactant to form the conductive layer for afirst period of time, (c) exposing the semiconductor substrate to areactant so that the reactant reacts with organic compounds containedwithin the conductive layer, and (d) reintroducing the precursor gasinto the CVD chamber following exposure of the semiconductor substrateto the reactant so as to further form the conductive layer on thesemiconductor device.

[0015] In one particular embodiment, a semiconductor device with adefined opening for a 3-dimensional capacitor is positioned within a CVDchamber and is exposed to a precursor gas containing platinum which isthen deposited using chemical vapor deposition techniques. A reactant isalso introduced into the CVD chamber wherein the deposited platinummaterial is exposed to the reactant. The reactant can comprise any of anumber of elements, compounds or processes, such as, for example, theintroduction of a gas such as H₂, N₂O, NO, H₂O, O₂, ozone, or some otheroxygen containing ambient, into the CVD chamber or with the enhancementof plasma or UV light. Moreover, the conductor can comprise not onlyplatinum, but also other conductive films such as Ir, Rh, Ni, Co, Cu, W,and the like.

[0016] In one embodiment, the reactant gas is introduced at the sametime as the conductive precursor gas. In another embodiment, thereactant gas is introduced following the introduction of the precursorgas for a selected period of time. In either circumstance, the reactantgas reacts with the residual organic compounds so as to remove theresidual organic compounds in or on the surface of the deposited filmsthereby increasing the deposition efficiency.

[0017] Organic by-products can be adhered to the exposed surface of thedeposited conductive layer. By introducing a reactant into the CVDchamber, the organic compounds can be removed by reaction with thereactants thereby making available more conductor nucleating sites andallowing greater absorption of the conductor precursor in the vaporphase.

[0018] In another aspect of the invention, a system for forming aconductive layer on a semiconductor device is provided. In this aspect,the system includes a CVD chamber which receives the semiconductordevice; a metal organic precursor gas source which provides a metalorganic precursor gas with entrained conductive particles; a reactantsource that provides a reactant to the CVD chamber and a controllerwhich controls the delivery of conductive precursor gas and reactantinto the CVD chamber. In this aspect, the controller allows for thedelivery of the conductive precursor gas and the reactant into thechamber. The reactant is selected to react with organic compounds of theconductive precursor gas so as to remove the organic compound from theformed conductive layer. Hence, by delivering both the precursor and thereactant, either simultaneously or sequentially or both, the efficiencyof the deposition process can be improved.

[0019] In one particular embodiment, the system includes a sensor, suchas, for example, a mass spectrometer, that provides a signal to thecontroller indicative of the deposition of the conductive precursor gasby the semiconductor device. When the deposition drops below aparticular threshold, such that there is increased waste of theconductive precursor gas, the controller then induces the delivery ofthe reactant into the chamber.

[0020] It will be appreciated that the aforementioned aspects of thepresent invention allow for more efficient formation of conductivelayers with more efficient deposition of conductive material at agreater cost saving. These and other objects and advantages of thepresent invention will become more fully apparent from the followingdescription taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a block diagram of one embodiment of a system forforming a conductive structure on a semiconductor device;

[0022] FIGS. 2A-2C are cross-sectional views of a semiconductor deviceillustrating one embodiment of a method by which a conductive structureis formed on the device;

[0023]FIG. 3A is an illustration of a typical platinum precursor gasmolecule used in a CVD process;

[0024]FIG. 3B is a chart illustrating the improved absorptioncharacteristics of the process of the illustrated embodiments;

[0025]FIG. 4 is a block diagram illustrating another embodiment of asystem for forming a conductive structure on a semiconductor device; and

[0026]FIG. 5 is a flow chart illustrating one method of forming aconductive structure on a semiconductor device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0027] Reference will now be made to the drawings wherein like numeralsrefer to like parts throughout. FIG. 1 is a block diagram whichillustrates one example of a system 100 for depositing a conductivelayer on a semiconductor device in accordance with the illustratedembodiment. As is illustrated in FIG. 1, a CVD chamber 101 of a typeknown in the art, is provided with a conductive precursor gas 105 thatis used to deposit conductive layers and structures on semiconductordevices positioned within the CVD chamber 101. In particular, aconductive carrier gas 103 containing conductive elements is provided bya conductive carrier gas source 102 and the conductive carrier gas 103is supplied to a bubbler 104 that contains a liquid precursor. Theconductive carrier gas 103 and the liquid precursor bind so as to allowthe conductive element to be carried in a gas form in the conductiveprecursor gas 105 into the CVD chamber 101 so as to permit CVD coverageof the semiconductor devices in a manner known in the art.

[0028] In one particular embodiment, the conductive carrier gas 103 is aknown platinum-based carrier gas, such as platinum entrained in N₂O. Theconductive carrier gas 103 is supplied to the bubbler 104 which, in thisembodiment, contains a liquid methyl based precursor such that theconductive precursor gas 105 is comprised of (methylcyclopentadienyl)(trimethyl) platinum (MeCpPtMe₃). The use of the organic methyl compoundin the conductive precursor gas 105 allows for better step coverageduring CVD deposition than just supplying a platinum carrier gasdirectly into the CVD chamber 101. As will be described in greaterdetail below, in one embodiment, the conductor precursor gas 105 issupplied to the CVD chamber 101 for a preselected period of time so asto allow the conductive element to coat the semiconductor device viachemical vapor deposition (CVD) techniques.

[0029] While in this embodiment, the conductive precursor gas 105 is aPlatinum conductive gas, it will be appreciated that any of a number ofdifferent precursor gases used to form conductive films can be usedwithout departing from the present invention. These gases include gasesthat entrain conductive elements such as Ir, Rh, Ni, Co, Cu, W, and thelike.

[0030] As is also illustrated in FIG. 1, the system 100 includes areactant source 106 that provides a reactant 107 into the CVD chamber101 that is selected so as to interact with the organic compounds of theconductive precursor gas 105 to thereby facilitate more efficientdeposition of the conductive elements contained within the conductiveprecursor gas 105. In one particular embodiment, the reactant source 106provides the reactant 107 selected from the group comprising NH₃, H₂,N₂, NO, N₂O, O₂, O₃, or any other O containing ambient. Providing thereactant 107 into the CVD chamber 101 allows the conductive elementscontained within the conductive precursor gas 105 to deposit on thesurface of the semiconductor device. Providing the reactant 107 into theCVD chamber 101, also results in the reactant 107 reacting with residualorganic compounds or other contaminants from the conductive precursorgas 105 that have been deposited on the conductive structure formedduring the CVD step thereby allowing for more efficient deposition ofconductive elements during subsequent chemical vapor deposition steps.As is also illustrated in FIG. 1, the illustrated system 100 alsoincludes a waste gas receptacle 110 that receives waste gas 111comprised of unused conductive precursor gas 105 and unused reactants107 during the process.

[0031] In the preferred process, the reactant 107 and the conductiveprecursor gas 105 are simultaneously introduced into the CVD chamber 101for a period of time that is selected to obtain a resulting conductivefilm of a desired thickness. When both the reactant 107 and theconductive precursor gas 105 are introduced into the chamber 101, thereactant 107 reacts with the contaminants contained within the film thatmay not otherwise be volatile enough at the deposition temperature andstay on the surface.

[0032] In one embodiment, the reactant 107 is an oxidizing agent, suchas NO, N₂O, O₂, or O₃, that reacts with the organic byproducts on thesurface to give them sufficient energy to become a gas that can beremoved as the waste gas 111. In other embodiments, the reactant 107 isa reducing agent such as NH₃ or H₂. In the specific application of usingplatinum, platinum is an active catalyst that absorbs hydrogen at itssurface and it activates the molecules enough to react with carbon ormethyl (CH₃) to form CH₄ and other hydrocarbons. The introduction of thereactant 107 helps to remove these other hydrocarbons.

[0033] In the preferred embodiment, the reactant 107 and the conductiveprecursor gas 105 are introduced into the chamber 101 simultaneouslyuntil a film of a desired thickness is achieved. It will, however, beappreciated that the precursor gas 105 and the reactant gas 107 can beintroduced sequentially until a film of a desired thickness is achievedwithout departing from the spirit of the present invention. It should beappreciated that introduced should be construed to mean both initiatingthe supply of an agent and also continuing to supply that agent for someperiod of time.

[0034] FIGS. 2A-2C schematically illustrate the process of theillustrated embodiment in greater detail. More particularly, FIGS. 2A-2Cprovide a simplified illustration of how a conductive layer 160, such asa lower electrode of a capacitor or a conductive, would be formed in anopening 156 that is adapted to receive, for example, a capacitor. As isillustrated in FIG. 2A, a semiconductor device 150, which can comprise asemiconductor substrate 152 with an insulating layer 154 positionedthereon, is positioned within the CVD chamber 101. In this particularsimplified example, the semiconductor device 150 includes the opening156 formed in the insulating layer 154 which is then to be coated withthe conductive layer 160.

[0035] As is illustrated in FIG. 2A, the conductive precursor gas 105 isintroduced into the CVD chamber 101 such that a conductive material,such as platinum, is deposited on the exposed surfaces of thesemiconductor device 150. Using the conductive precursor gas 105illustrated in FIG. 4 results in a relatively high degree of stepcoverage of the conductive layer 160 on the horizontal surfaces and alsoon the vertical side wall surfaces of the semiconductor device 150. Asis also schematically represented in FIG. 2A, the initial deposition ofthe conductive layer 160 results in organic compounds 162 occupying thesurface nucleating sites of the conductive layer 160. In particular, forthe conductive precursor gas 105 illustrated in FIG. 3A, the organiccompound 162 that comprises the methyl molecules poisons the exposedsurface of the conductive layer 160 by covering the available platinumnucleating sites or by otherwise inhibiting further absorption of theconductive precursor gas 105 in the vapor phase.

[0036] As is also schematically illustrated in FIG. 2A, the reactant 107is introduced into the CVD chamber 101 as the conductive precursor gas105. The reactant 107 preferably reacts with the organic compounds 162thereby removing these compounds in the previously described manner toimprove the deposition efficiency of the process. The processillustrated in FIG. 2A can thus be continued until a conductive layer160 of a desired thickness is achieved. The simultaneous introduction ofthe conductive precursor gas 105 and the reactant 107 results in moreefficient deposition as is illustrated in the chart of FIG. 3B discussedhereinbelow.

[0037] As was also discussed above, the reactant 107 can also beintroduced after the conductive precursor gas 105 has been introducedfor a set period of time in the manner shown in FIG. 2B. Specifically,the conductive precursor gas 105 can be initially introduced and thereactant 107 can then be introduced subsequently to remove thecontaminants 162 and the conductive precursor gas 105 can then bereintroduced again.

[0038] For example, once the conductive layer 160 is no longerefficiently absorbing the conductive elements of the conductiveprecursor gas 105, the flow of the conductive precursor gas 105 into theCVD chamber 101 is stopped and the semiconductor device 150 within theCVD chamber 101 is then exposed to a reactant 107 from the reactantsource 106. Preferably, the reactant source 106 is selected to provide areactant 107 that reacts with the organic compounds 162 of theconductive precursor gas 105 so as to remove at least some of theorganic compounds 162 from conductive element nucleation sites withinthe conductive layer 160. In certain embodiments, the reactant 107, asintroduced subsequent to cessation of introduction of the conductiveprecursor gas 105, comprises a reactant 107 selected from the groupcomprising N₂O, O₂, H₂, NH₃, NO, H₂O, ozone, vacuum, and inert gaspurge, such as with N₂ or argon. In certain embodiments, the reactant107 also comprises providing supplemental plasma treatment and/or UVlight to the CVD chamber 101.

[0039] It will be appreciated that in certain embodiments, the reactant107 as introduced with the conductive precursor gas 105 comprises thesame reactant 107 as introduced absent the introduction of theconductive precursor gas 105. In other embodiments, the reactant 107 asintroduced absent the introduction of the conductive precursor gas 105comprises alternative or additional components as the reactant 107 asintroduced with the conductive precursor gas 105.

[0040] As illustrated in FIG. 2C, subsequent to the exposure of theconductive layer 160 to the reactant 107, the reactant source 106 stopsproviding the reactant 107 into the CVD chamber 101 and the conductiveprecursor gas 105 is again provided into the CVD chamber 101 in thepreviously described manner. This results in further deposition of theconductive elements contained within the conductive precursor gas 105 soas to result in greater deposition of the conductive elements. Since thereactant 107 has removed at least some of the organic compounds 162 fromthe conductive layer 160 that would otherwise inhibit further chemicalvapor deposition of the conductive elements of the conductive precursorgas 105, more conductive elements can be added to the conductive layer160 by a subsequent chemical vapor deposition step.

[0041] Hence, the process of forming the conductive layer 160 in thisembodiment can either comprise introducing a conductive precursor gas105 and a reactant 107 simultaneously into the CVD chamber 101 for apreselected period of time to form a conductive structure orsequentially introducing a conductive precursor gas 105 and a reactant107 to form the conductive structure 160.

[0042] In one particular example, a conductive layer 160 is formed usingan initial deposition step wherein a platinum precursor carrier gas isprovided from the conductive carrier gas source 102 through the bubbler104 at a rate of between 40 to 200 sccm with the platinum beingencapsulated within a helium carrier. The bubbler 104 contains a liquidprecursor at a temperature between 35° C. and 50° C., such that theresulting conductive precursor gas 105 emanating from the bubbler 104has the chemical composition as illustrated in FIG. 3A. The resultingconductive precursor gas 105 is provided from the bubbler 104 to the CVDchamber 101 along with a simultaneous flow of N₂O reactant 107 at a rateof 100 to 800 sccm from the reactant source 106. This flow of conductiveprecursor gas 105 and reactant 107 is provided to the CVD chamber 101for approximately 50 seconds to result in deposition of the conductivelayer 160. At the end of the 50 second period, the flow of theconductive precursor gas 105 from the bubbler 104 is ceased while theflow of the N₂O reactant 107 from the reactant source 106 is continuedfor 10 seconds. The N₂O thus comprises the reactant 107 which reactswith the organic compounds 162 in the deposited layer 160 associatedwith the conductive precursor gas 105 so as to remove the organiccompounds 162 from the deposited, conductive layer 160 in the mannerdescribed in conjunction with FIG. 2B.

[0043] Subsequently, the conductive precursor gas 105 is provided foranother 50 second interval and is then followed by a 10 second exposureof the conductive layer 160 to the N₂O reactant 107 from the reactantsource 106. This process is repeated until a conductive layer 160 of adesired thickness is formed.

[0044] Repeating the above-described exemplary process for threeiterations results in the deposition of a platinum conductive layer 160that has a resistivity of approximately 1.1 Ohm/sq. With the sameprocessing parameters and devices, a single step CVD deposition thatdoes not include either simultaneous or sequential introduction ofreactant 107 for the same overall duration results in a conductive layerhaving a resistivity on the order of 17 Ohm/sq.

[0045] It will be understood that resistivity of the depositedconductive layer 160 is inversely proportional to the thickness of theconductive layer 160 which indicates that there is a very significantincrease in the deposition rate of the film using the process of theabove-described embodiment. In fact, the Applicant has observed at leastten-fold increases in the deposition rate over known CVD depositiontechniques for conductive layers of this type. Hence, there is asignificant savings both in terms of reduced waste of the conductiveprecursor gas 105 and also reduced processing time to form conductivelayers 160 of a desired thickness using the CVD deposition technique 100described herein.

[0046]FIG. 3B is a diagram which illustrates the advantages of usingboth a conductive precursor gas 105 and a reactant gas 107 in formingconductive layers 160. FIG. 3B is a chart that is illustrative of theResistivity (Rs) of films of either Pt or PtRh with multiple depositionsteps. The total deposition time for the process illustrated in FIG. 3Bis 300 seconds where the conductive precursor gas 105 is introduced for50 seconds in combination with the reactant 107 and then for 10 secondsthe reactant 107 is maintained by itself in the chamber 101. As isillustrated, there is a significant decrease in the resistivity which isindicative of an increase in the thickness of the film as compared to asingle step, 300 second deposition without the introduction of areactant 107.

[0047] In the specific example described above, the conductive precursorgas 105 is introduced simultaneously with the reactant 107 and then thereactant 107 is introduced for a limited period of time by itself toimprove the deposition rate of the process. It will be appreciated thatthe system can either have the combined conductive precursor gas105/reactant 107 introduced for a selected time period followed byintroduction of the reactant 107 alone for a selected time period or thesystem can monitor the rate of absorption of the conductive precursorgas 105 and, when it falls below a desired threshold, increase theconcentration or change the composition of the reactant 107 which canthen be followed by reintroduction of the conductive precursor gas 105.

[0048] For example, as is illustrated in FIG. 4, a CVD system 200includes a CVD chamber 201 that receives the conductor precursor gas 205from a bubbler 204 wherein the bubbler 204 is supplied with theconductive carrier gas 203 from the conductive carrier gas source 202 inthe previously described manner. Similarly, the reactant 207 isintroduced into the CVD chamber 201 from a reactant source 206 and wastegas 211 is supplied to a waste gas receptacle 210 in the previouslydescribed manner. A controller 212, such as a microprocessor, controlsthe operation of the CVD system 200. Moreover, the controller 212receives a signal from the waste gas receptacle 210 that is indicativeof the quantity of the conductive precursor gas 205 that is not beingdeposited onto or absorbed by the conductive layer 160 of thesemiconductor device 150 and is, thus, being received by the waste gasreceptacle 210. For example, a mass spectrometer can be installed in thewaste gas receptacle 210 so as to provide an indication of the quantityof the conductive precursor gas 205 that is not being deposited onto theconductive layer 160. This signal can then be used by the controller 212to determine when to deliver the reactant 107 into the CVD chamber 201.The signal can also be used to determine the appropriate composition ofthe reactant(s) 107 to be supplied to the CVD chamber 201.

[0049]FIG. 5 is a flow chart illustrating an exemplary manner ofoperation of the CVD system 200 of FIG. 4. From a start state 300 thesemiconductive device 150 is initially positioned, in state 302, withinthe CVD chamber 201. Subsequently, the conductive precursor gas 105 isintroduced, in state 304, into the CVD chamber 201. The conductiveprecursor gas 105 can be introduced in state 304 alone or in combinationwith the reactant 107 as discussed previously.

[0050] The controller 212 can then determine, in decision state 306,whether the absorption rate, indicative of the proportion of theconductive precursor gas 105 being deposited to form the conductivelayer 160, is above a preselected absorption rate. This determinationcan be based upon analysis of the conductive precursor gas 105 beingreceived by the waste gas receptacle 210 as described above.

[0051] If the controller 212 determines, in decision state 306, that theabsorption rate is above a preselected threshold, the conductiveprecursor gas 105 continues to be supplied into the CVD chamber 201 instate 304. However, if the controller 212 determines, in decision state306, that the absorption rate has decreased below the preselectedthreshold, the controller 212 then determines, in decision state 310,whether the conductive layer 160 is at a desired thickness. Thecontroller 212 can, for example, make this determination by comparingthe elapsed time of the deposition cycle to empirically determineddeposition rates for the particular conductive precursor gas 105. If thecontroller 212 determines, in decision state 310, that the thickness ofthe conductive layer 160 is the desired thickness, the process thenproceeds to an end state 314 allowing the semiconductor device 150 to beremoved from the CVD chamber 201. It will be appreciated that it may bedesirable to introduce the reactant 107 into the CVD chamber 201 priorto removal of the semiconductor device 150 from the CVD chamber 201 soas to remove at least some of the organic compounds 162 prior to asubsequent processing step.

[0052] However, if the absorption rate has dropped below the optimum andthe conductive layer 160 is not at the desired thickness, the controller212 can, in state 312, then cease delivery of the conductive precursorgas 105 into the CVD chamber 201 and provide only the reactant 107 intothe CVD chamber 201 for a predetermined period of time to enhance theremoval of the organic compounds 162 in the conductive layer 160.Subsequently, the conductive precursor gas 105 can be reintroduced intothe CVD chamber 201, in state 304, for a subsequent deposition of theconductive layer 160. In this way, intelligent control of the CVD system200 can be obtained thereby resulting in more efficient chemical vapordeposition of conductive layers 160 and structures onto thesemiconductor device 150.

[0053] From the foregoing, it will be appreciated that theabove-described process illustrates a manner of forming a conductivelayer 160 or structure on a semiconductor device 150 that results inmore efficient use of conductive precursor gas 105. This results insignificantly less waste of the conductive precursor gas 105 resultingin cost savings for the manufacturing process. Moreover, the improvedefficiencies can also result in faster formation of the conductivelayers 160 resulting in improved manufacturing efficiencies.

[0054] Although the foregoing description of the preferred embodiment ofthe present invention has shown, described and pointed out thefundamental novel features of the invention, it will be understood thatvarious omissions, substitutions and changes in the form of the detailof the apparatus as illustrated as well as the uses thereof, may be madeby those skilled in the art without departing from the spirit of thepresent invention. Consequently, the scope of the present inventionshould not be limited to the foregoing discussions, but should bedefined by the appended claims.

What is claimed is:
 1. A method of forming a conductive layer on asemiconductor device, the method comprising: (i) positioning asemiconductor device within a chemical vapor deposition chamber; (ii)introducing a conductive precursor gas into the chemical vapordeposition chamber for a first period of time; (iii) introducing areactant into the chemical vapor deposition chamber for a second periodof time, so that the conductive layer is formed on the semiconductordevice and organic waste compounds positioned within and on theconductive layer of the first thickness are removed; and (iv) continuingacts (ii) and (iii) until the conductive layer of a desired thickness isachieved.
 2. The method of claim 1, wherein positioning thesemiconductor device within the chemical vapor deposition chambercomprises positioning a semiconductor wafer having an isolation regionwith a 3-dimensional opening formed therein in the chemical vapordeposition chamber so that inner walls of the 3-dimensional opening canbe coated with the conductive layer so as to form an electrode of acapacitor.
 3. The method of claim 1, wherein introducing the conductiveprecursor gas into the chemical vapor deposition chamber comprisesintroducing a platinum precursor gas into the chemical vapor depositionchamber.
 4. The method of claim 3, wherein introducing the platinumprecursor gas into the chemical vapor deposition chamber comprisesintroducing a platinum precursor gas into the chemical vapor depositionchamber wherein the platinum is bonded to a methyl compound so as toimprove the step coverage of the platinum precursor gas when forming theconductive layer.
 5. The method of claim 4, wherein introducing theplatinum precursor gas comprises introducing a(methylcyclopentadienyl)(trimethyl) platinum gas into the chemical vapordeposition chamber.
 6. The method of claim 1, wherein introducing thereactant into the chemical vapor deposition chamber comprisesintroducing a reactant that reacts with residual organic compoundsprovided by the conductive precursor gas that are bonded to the surfaceof the conductive layer so as to remove at least some of the organiccompounds to thereby facilitate further deposition of conductivecomponents of the conductive precursor gas upon re-introduction of theconductive precursor gas into the chemical vapor deposition chamber. 7.The method of claim 6, wherein introducing the reactant into thechemical vapor deposition chamber comprises introducing the reactantsimultaneously with the conductive precursor gas.
 8. The method of claim7, wherein introducing the reactant into the chemical vapor depositionchamber comprises introducing the reactant both simultaneously with theconductive precursor gas and sequentially to the conductive precursorgas.
 9. The method of claim 6, wherein the reactant is a reducing agent.10. The method of claim 6, wherein the reactant is an oxidizing agent.11. The method of claim 6, wherein introducing the reactant comprisesintroducing a reactant selected from the group comprising N₂O, O₂, H₂,NH₃, NO, H₂O, and ozone.
 12. The method of claim 1, further comprising:monitoring the rate of deposition of the conductive layer; determiningwhen the rate of deposition has decreased beneath a desired threshold;halting the supply of conductive precursor gas upon determining that therate of deposition is less than the desired threshold; and providingonly the reactant after halting the supply of the conductive precursorgas.
 13. The method of claim 12, wherein monitoring the rate ofdeposition of the conductive precursor gas comprises monitoring theamount of conductive components in the conductive precursor gas thatarrives at a waste receptacle following introduction of the conductiveprecursor gas into the chemical vapor deposition chamber.
 14. The methodof claim 13, wherein monitoring the amount of conductive components inthe conductive precursor gas that arrives at a waste receptaclecomprises using a mass spectrometer to obtain a measurement indicativeof the amount of conductive components of the conductive precursor gasthat arrives at the waste receptacle.
 15. The method of claim 12,wherein providing only the reactant after halting the supply of theconductive precursor gas comprises providing at least one reactantselected from the group comprising N₂O, O₂, H₂, NH₃, NO, H₂O, ozone,plasma, vacuum, inert gas, and UV light.
 16. A method of forming aconductive layer, the method comprising: (i) positioning a semiconductordevice within a chamber; (ii) introducing a conductive precursor gas,having a conductive component and organic components, and a reactantinto the chamber so that the conductive component covers an exposedregion of the semiconductor device and forms the conductive layer on theexposed region of the semiconductor device; (iii) ceasing theintroduction of the conductive precursor gas and continuing theintroduction of the reactant, wherein the reactant reacts with organiccomponents of the conductive precursor gas that have bonded to theconductive layer so as to inhibit further deposition of the conductivecomponents of the conductive precursor gas on the conductive layer sothat the reactant removes at least some of the organic compounds fromthe conductive layer; and (iv) reintroducing the conductive precursorgas with the reactant into the chamber following reaction of thereactant with the organic components so as to further deposit conductivecomponents on the conductive layer to thereby increase the thickness ofthe conductive layer.
 17. The method of claim 16, wherein positioning asemiconductor device within the chamber comprises positioning asemiconductor wafer having an isolation region with a 3-dimensionalopening formed therein in a chemical vapor deposition chamber so thatthe inner walls of the 3-dimensional opening can be coated with theconductive layer so as to form an electrode of a capacitor.
 18. Themethod of claim 16, wherein introducing a conductive precursor gas intothe chamber comprises introducing a platinum precursor gas into achemical vapor deposition chamber.
 19. The method of claim 18, whereinintroducing the platinum precursor gas into the chamber comprisesintroducing a platinum precursor gas into the chamber wherein theplatinum is bonded to a methyl compound so as to improve the stepcoverage of the conductive layer when forming the conductive layer. 20.The method of claim 19, wherein introducing the platinum precursor gascomprises introducing a (methylcyclopentadienyl)(trimethyl) platinum gasinto the chemical vapor deposition chamber.
 21. The method of claim 16,wherein introducing the reactant comprises introducing a reactantselected from the group comprising N₂O, O₂, H₂, NH₃, N₂O, NO, H₂O, andozone into the chamber.
 22. The method of claim 16, wherein introducingand reintroducing the conductive precursor gas into the chambercomprises introducing and reintroducing the conductive precursor gas fora pre-selected period of time.
 23. The method of claim 22, furthercomprising (v) ceasing the introduction of the conductive precursor gasand continuing the introduction of the reactant following (iv)reintroducing the conductive precursor gas with the reactant into thechamber.
 24. The method of claim 23, wherein the acts (ii) through (v)are repeated until a conductive layer of a desired thickness is formedon the semiconductor device.
 25. The method of claim 24, whereinintroducing the conductive precursor gas and reintroducing theconductive precursor gas comprises introducing the gas at a rate ofapproximately 40-200 sccm of a platinum precursor gas for approximately50 seconds and wherein introducing the reactant comprises introducingN₂O at a rate of approximately 100-800 sccm for approximately 10 secondsinto the chamber.
 26. The method of claim 25, wherein introducing theconductive precursor gas comprises introducing the gas at a rate of40-200 sccm of a platinum precursor gas for approximately 50 secondssimultaneously with introducing the reactant gas of N₂O at a rate ofapproximately 100-800 sccm and wherein introducing the reactant gasfurther comprises maintaining the introduction of the reactant gas inthe chamber for 10 seconds following the introduction of the platinumprecursor gas.
 27. The method of claim 16, further comprising:monitoring the rate of deposition of the conductive components of theconductive precursor gas on the conductive layer; determining when therate of deposition has decreased beneath a desired threshold; haltingthe supply of conductive precursor gas to the chamber upon determiningthat the rate of deposition is less than the desired threshold;introducing the reactant after halting the supply of the conductiveprecursor gas.
 28. The method of claim 27, wherein monitoring the rateof deposition of the conductive precursor gas comprises monitoring theamount of conductive components in the conductive precursor gas thatarrives at a waste receptacle following introduction of the conductiveprecursor gas into the chamber.
 29. The method of claim 28, whereinmonitoring the amount of conductive components in the conductiveprecursor gas that arrives at a waste receptacle comprises using a massspectrometer to obtain a measurement indicative of the amount ofconductive components of the conductive precursor gas that arrives at awaste receptacle.
 30. The method of claim 23, wherein introducing thereactant in steps (ii) and (iv) comprises introducing a reactantselected from the group comprising N₂O, O₂, H₂, NH₃, N₂O, NO, H₂O, andozone and introducing a reactant in steps (iii) and (v) comprisesintroducing at least one reactant selected from the group comprisingN₂O, O₂, H₂, NH₃, NO, H₂O, ozone, plasma, vacuum, inert gas, and UVlight.
 31. A system for forming a conductive element on a semiconductordevice, the system comprising: a chamber that receives the semiconductordevice; a conductive precursor gas supply system that provides aconductive precursor gas to the chamber wherein the conductive precursorgas has both conductive components that when deposited on thesemiconductor device form the conductive element and organic componentswhich facilitate step coverage of the conductive elements over thesemiconductor device; and a reactant supply system that introduces areactant into the chamber that is selected to enable deposition of theconductive components of the conductive precursor gas on thesemiconductor device and to remove organic components off of theconductive element to facilitate further deposition of conductivecomponents of the conductive precursor gas on the conductive element.32. The system of claim 31, wherein the chamber is a chemical vapordeposition chamber and wherein the conductive element is formed throughchemical vapor deposition.
 33. The system of claim 32, wherein theconductive precursor gas supply system includes a carrier gas supplydevice that supplies the conductive element in a gas form and a liquidprecursor system that receives the carrier gas and produces theconductive precursor gas for delivery to the chamber.
 34. The system ofclaim 33, wherein the conductive precursor gas supply system provides aplatinum precursor gas into the chamber.
 35. The system of claim 34,wherein the conductive precursor gas supply system provides a platinumprecursor gas into the chamber wherein the platinum is bounded to amethyl compound so as to improve the step coverage of the platinum whenforming the conductive element.
 36. The system of claim 35, wherein theconductive precursor gas supply system introduces a(methylcyclopentadienyl)(trimethyl) platinum gas into the chemical vapordeposition chamber.
 37. The system of claim 31, wherein the reactantsupply system introduces a reactant selected from the group comprisingN₂O, O₂, H₂, NH₃, NO, H₂O, and ozone.
 38. The system of claim 31,further comprising a controller that controls the delivery of theconductive precursor gas and the reactant into the chamber.
 39. Thesystem of claim 38, wherein the controller simultaneously introduces theconductive precursor gas and the reactant into the chamber until theconductive element has a desired thickness.
 40. The system of claim 39,wherein the controller sequentially introduces the conductive precursorgas and the reactant into the chamber for a first time period, thenhalts the delivery of the conductive precursor gas and only introducesthe reactant for a second time period.
 41. The system of claim 40,wherein the reactant introduced during the second time period comprisesat least one reactant selected from the group comprising N₂O, O₂, H₂,NH₃, NO, H₂O, ozone, plasma, vacuum, inert gas, and UV light.
 42. Thesystem of claim 38, further comprising a sensor that provides a signalindicative of the rate of deposition of the conductive element of theconductive precursor gas on the semiconductor device during formation ofthe conductive element.
 43. The system of claim 42, wherein thecontroller receives the signal from the sensor and uses the signal todetermine when to halt delivery of the conductive precursor gas.
 44. Thesystem of claim 43, wherein the sensor comprises a mass spectrometerthat measures the amount of waste conductive element of the conductiveprecursor gas and provides a signal indicative thereof.